Abstract: The centralized control system currently applied by Matou Plant cannot meet the actual needs of the plant′s coal washing operations because of the mismatched relationship between the hard and soft locking control systems as well as the diverse and complicated procedures for the centralized control system (CCS) to carry out start/stop of equipment. To deal with the situation, work is made on technical transformation of the CCS′s locking control mode, based on an reinvestigation of the CCS and the coal washing equipment in current use. Through optimization of CCS, switching the connection of hard and soft locking systems from a series to a parallel mode, and adding change-over switches on part of key equipment, the transformation work has been successfully made by the technical personnel of the plant. The transformation has led to a save of around 0.5 million yuan of transformation cost, a cut of 50,000 yuan of labor cost per year, shortening of idle-running time of equipment caused by mechanical failure of some equipment, prevention of fluctuation of quality of clean coal products and greater safety of overall plant operations. After the soft and hard locking systems are in correct relationship, all the equipment of the plant can be put under proper pocking control irrespective of their operating state, effectively enhancing as a result the practically and safety of equipment locking operations. The transformation work made by Matou Plant provides a new thought and also valuable reference for other plants to make similar transformation work.